Hey, any HR guys spinning well past 7500rpms
perhaps?
01-17-2011, 08:31 PM
#84
Alright as soon as my tax return is here...... I think I've got the perfect combo for a 7500 rpm HR valvetrain. It will be a beehive spring, and i think .700 lift is doable. It can run a NASTY lobe if you wanted to stay under the 7000 limit. It will need a 3/8" pushrod, a short travel lifter, and titanium retainers, however.
01-17-2011, 11:45 PM
#86
Alright as soon as my tax return is here...... I think I've got the perfect combo for a 7500 rpm HR valvetrain. It will be a beehive spring, and i think .700 lift is doable. It can run a NASTY lobe if you wanted to stay under the 7000 limit. It will need a 3/8" pushrod, a short travel lifter, and titanium retainers, however.
.Curious to see what beehive you found with a high enough in/lb rate to keep the closed seat pressure modest but still pull enough open pressure to control an unruly 7500rpm HR setup. I know they say beehives can use quite a bit less open pressures then a standard spring(~10% less #'s?), but I imagine it's still going to take some pressure to keep everything playing nicely.
Good luck! I definitely think you would be one of the few that can make it work.
01-18-2011, 07:35 PM
#87
Go for it .
Curious to see what beehive you found with a high enough in/lb rate to keep the closed seat pressure modest but still pull enough open pressure to control an unruly 7500rpm HR setup. I know they say beehives can use quite a bit less open pressures then a standard spring(~10% less #'s?), but I imagine it's still going to take some pressure to keep everything playing nicely.
Good luck! I definitely think you would be one of the few that can make it work.
.Curious to see what beehive you found with a high enough in/lb rate to keep the closed seat pressure modest but still pull enough open pressure to control an unruly 7500rpm HR setup. I know they say beehives can use quite a bit less open pressures then a standard spring(~10% less #'s?), but I imagine it's still going to take some pressure to keep everything playing nicely.
Good luck! I definitely think you would be one of the few that can make it work.
01-19-2011, 12:30 PM
#89
the spring and retainer mass is about 50 grams lighter than a 1243 setup, but effectively it's even lighter as only the small retainer and top coils are compressing. A dual spring would need roughly 100# more open pressure to do the same here, plus the resonance of the progressive rate beehive spring will have an advantage in valve control as well. Seat pressures will be roughly 200 lbs, open will be 480+. This spring has gone 8400+ in real street stuff.
01-19-2011, 12:52 PM
#90
the spring and retainer mass is about 50 grams lighter than a 1243 setup, but effectively it's even lighter as only the small retainer and top coils are compressing. A dual spring would need roughly 100# more open pressure to do the same here, plus the resonance of the progressive rate beehive spring will have an advantage in valve control as well. Seat pressures will be roughly 200 lbs, open will be 480+. This spring has gone 8400+ in real street stuff.
01-19-2011, 02:08 PM
#91
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just out of curiousity...........why stay HR??? I mean a correctly built SR doesn't need crazy valve train killing spring pressures......i've got a mere 220# at the seat on mine and it remains stable over 8000rpm......its been to 8300+ before........just saying why all the HR stuff.......be same price if not cheaper to go SR instead of all this hi-tech hi dollar HR stuff.......plus the SR will make more power anyway
I've been reading this thread and thinking exactly the same thing....
01-19-2011, 02:59 PM
#92
I feel the same I just can't understand the fascination to go hr and rev high. My first lt4 build went 7200 and would shut down. This is in a stock PCM 93 vette (tuned chip). It made peak at 6600 and the dyno curve showed nothing to gain over that but I didnt care and wanted to grenade it.
Next build was a 388 lt4 sr though with big block beehives. Cam was pretty mild .588 230/244 or so and it peaked 6800 and carried pretty well to 7100 or so. I have plenty datalogs and dyno runs where I pushed it to the limited at 7800 but this was all with a dfi gen7. Motor blew up after a flopped lash adjustment that ended up in a split retainer dropping a valve at 7k + rpm.
Next build is almost done and will handle 8k but it's a sr and noone wants to hear about it cuz it's not a hr right ?
Next build was a 388 lt4 sr though with big block beehives. Cam was pretty mild .588 230/244 or so and it peaked 6800 and carried pretty well to 7100 or so. I have plenty datalogs and dyno runs where I pushed it to the limited at 7800 but this was all with a dfi gen7. Motor blew up after a flopped lash adjustment that ended up in a split retainer dropping a valve at 7k + rpm.
Next build is almost done and will handle 8k but it's a sr and noone wants to hear about it cuz it's not a hr right ?
01-19-2011, 03:04 PM
#94
the spring and retainer mass is about 50 grams lighter than a 1243 setup, but effectively it's even lighter as only the small retainer and top coils are compressing. A dual spring would need roughly 100# more open pressure to do the same here, plus the resonance of the progressive rate beehive spring will have an advantage in valve control as well. Seat pressures will be roughly 200 lbs, open will be 480+. This spring has gone 8400+ in real street stuff.
01-19-2011, 05:04 PM
#95
I've been going waaaayyyyyyyyy over 7500 safely for 2 years now.....
just out of curiousity...........why stay HR??? I mean a correctly built SR doesn't need crazy valve train killing spring pressures......i've got a mere 220# at the seat on mine and it remains stable over 8000rpm......its been to 8300+ before........just saying why all the HR stuff.......be same price if not cheaper to go SR instead of all this hi-tech hi dollar HR stuff.......plus the SR will make more power anyway
just out of curiousity...........why stay HR??? I mean a correctly built SR doesn't need crazy valve train killing spring pressures......i've got a mere 220# at the seat on mine and it remains stable over 8000rpm......its been to 8300+ before........just saying why all the HR stuff.......be same price if not cheaper to go SR instead of all this hi-tech hi dollar HR stuff.......plus the SR will make more power anyway
Cool the SR can make more power, but not everyone wants a solid roller! All the blah blah about quality components and matched setup only goes so far. The truth of the matter is, ANY solid roller lifter has a limited lifespan, and its hard to predict failure. That's the fact of a lash-type valvetrain, the needles eventually get pounded out of shape.If an 8000 rpm setup is lasting, then it's mild! Throw an HXL or TK lobe in there at the same .700 lift and it'll kill lifters and valvesprings in 1000 miles and probably float to destruction at 7500. Why not throw a more aggressive HR package together and close the gap to the less aggressive SR stuff and still come out cheaper and more reliable? The LSx guys are doing it, granted on a 55mm core, but why do we NEED to solid roller stuff just to make big power?
My New setup I went to a solid roller tho,I didnt think that the hr would live to 8800+ rpm.
01-19-2011, 07:23 PM
#98
I plan to carefully monitor my valvetrain for wear to see just how well it will hold up with an SR lobe @ over .7 lift.
Billet SR cam(bullet grind, unsure of lobe but I'll post when it arrives)
Comp Endure-X lifters
Trend .135 3/8 pushrods
1.7 shaftmounts(makes lobe seem more aggressive)
Will most likely shift @ around 8k, since Llyod said I can, and I quote "spin it to wherever you want with a 383 and those heads"
.
Billet SR cam(bullet grind, unsure of lobe but I'll post when it arrives)
Comp Endure-X lifters
Trend .135 3/8 pushrods
1.7 shaftmounts(makes lobe seem more aggressive)
Will most likely shift @ around 8k, since Llyod said I can, and I quote "spin it to wherever you want with a 383 and those heads"
.
01-19-2011, 07:54 PM
#99
Because if you are making BIG power you will make BIGGER Power going SR. I also cannot believe people are concerned with the sr shortcomings and at the same time putting huge cams and hr killing springs in and trying to rev high.
It's like trying to run faster by strapping a heavy backpack on and going to the gym and doing squats for more power.
It's like trying to run faster by strapping a heavy backpack on and going to the gym and doing squats for more power.
01-19-2011, 08:42 PM
#100
Because if you are making BIG power you will make BIGGER Power going SR. I also cannot believe people are concerned with the sr shortcomings and at the same time putting huge cams and hr killing springs in and trying to rev high.
It's like trying to run faster by strapping a heavy backpack on and going to the gym and doing squats for more power.
It's like trying to run faster by strapping a heavy backpack on and going to the gym and doing squats for more power.